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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_000_007_703">&nbsp;</a>NAME</h4><blockquote>
modf - decompose a floating-point number
</blockquote><h4><a name = "tag_000_007_704">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;<a href="math.h.html">math.h</a>&gt;

double modf(double <i>x</i>, double *<i>iptr</i>);
</code>
</pre>
</blockquote><h4><a name = "tag_000_007_705">&nbsp;</a>DESCRIPTION</h4><blockquote>
The
<i>modf()</i>
function
breaks the argument x into integral and fractional parts, each of
which has the same sign as the argument. It stores the integral part as a
double in the object pointed to by
<i>iptr</i>.
<p>
An application wishing to check for error situations should set
<i>errno</i>
to 0 before calling
<i>modf()</i>.
If
<i>errno</i>
is non-zero on return, or the return value is NaN, an error has occurred.
</blockquote><h4><a name = "tag_000_007_706">&nbsp;</a>RETURN VALUE</h4><blockquote>
Upon successful completion,
<i>modf()</i>
returns the signed fractional part of
<i>x.</i>
<p>
If
<i>x</i>
is NaN, NaN is returned,
<i>errno</i>
may be set to [EDOM] and
<i>*iptr</i>
is set to NaN.
<p>
If the correct value would cause underflow, 0 is returned and
<i>errno</i>
may be set to [ERANGE].
</blockquote><h4><a name = "tag_000_007_707">&nbsp;</a>ERRORS</h4><blockquote>
The
<i>modf()</i>
function may fail if:
<dl compact>

<dt>[EDOM]<dd>
The value
of
<i>x</i>
is NaN.

<dt>[ERANGE]<dd>
The result underflows.

</dl>
<p>
No other errors will occur.
</blockquote><h4><a name = "tag_000_007_708">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_709">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_007_710">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="frexp.html">frexp()</a></i>,
<i><a href="isnan.html">isnan()</a></i>,
<i><a href="ldexp.html">ldexp()</a></i>,
<i><a href="math.h.html">&lt;math.h&gt;</a></i>.
</blockquote><h4>DERIVATION</h4><blockquote>
Derived from Issue 1 of the SVID.
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UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
<br> [ <a href="../index.html">Main Index</a> | <a href="../xshix.html">XSH</a> | <a href="../xcuix.html">XCU</a> | <a href="../xbdix.html">XBD</a> | <a href="../cursesix.html">XCURSES</a> | <a href="../xnsix.html">XNS</a> ]

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